Wonju DB Promy (2013–2021) Doo was drafted third overall in the
2013 KBL rookie draft by
Wonju Dongbu Promy. The first two picks were his Kyung Hee teammates Kim Jong-kyu and Kim Min-goo, marking a rare occasion in which the first three picks of a draft came from the same university and not from a traditional "big 3" college basketball program (
Yonsei,
Korea and
Chung-Ang). The
2017-18 season was Doo's breakthrough season as he averaged 16.45 points and 3.8 assists. DB topped the league table and reached the play-off finals but lost to
Seoul SK Knights. Doo won the KBL Most Valuable Player Award and was voted into the Best 5. Doo enlisted for
mandatory military service in May 2018 and was assigned to the after completing basic training. He formed a partnership with shooting guard
Heo Ung and his college teammate
Kim Jong-kyu, who had joined DB that season. However, the season ended prematurely and play-offs were canceled due to the
COVID-19 pandemic; the results for the 2019–20 season were forfeited, although DB finished at the top of the league table. The 2020–21 season was forgettable as injuries ravaged key players. DB ended the season at 9th place, second last in the league table. In the January game against
Goyang Orions, Doo scored a
buzzer beater with 1 second left on the clock to win the game 92–90; it was voted Play of the Season at the annual KBL awards ceremony. He was traded to
Daegu KOGAS Pegasus, formerly Incheon Electroland Elephants, for
Kang Sang-jae and
Park Chan-hee.
Daegu KOGAS Pegasus (2021–2023) Doo did not play much during the first several games as he was still recovering from an injury and not in peak condition. He struck a back court partnership with Kim Nak-hyun, his experience complementing Kim's pace.
Wonju DB Promy (2023–2024) Changwon LG Sakers (2024-) National team Doo has mostly been a reserve guard for the national team due to the presence of veterans
Park Chan-hee and
Kim Sun-hyung and later the emergence of
Choi Jun-yong,
Heo Hoon and Kim Nak-hyun. He participated in the qualifiers for the 2017 FIBA Asia Cup, 2018 Asian Games and the 2019 FIBA World Cup but never made the final 12-man squad for any of the tournaments. ==Personal life==